New and undisclosed security measures will be imposed on airports flying passengers from Europe to the United States, amid concerns of increased risk of attack from al-Qaeda or other Islamist-affiliated groups.
Security will be tightened here in the UK, but the threat level has not been altered, the government said.
US security officials believe that the threat of new types of bombs being smuggled on board planes has grown, but would not give details on what exactly has triggered the precautions.
More top news
Thunderstorms affect many throughout the rest of the Bank Holiday weekend.
Police have released CCTV images of the Manchester suicide bomber on the night of the arena attack.
The grieving father of a teenage victim of the Manchester bombing told a mother hugging her son: “Look after him - because you never know.”